Dose factor entry and display tool for BNCT radiotherapy

Abstract

A system for use in Boron Neutron Capture Therapy (BNCT) radiotherapy planning where a biological distribution is calculated using a combination of conversion factors and a previously calculated physical distribution. Conversion factors are presented in a graphical spreadsheet so that a planner can easily view and modify the conversion factors. For radiotherapy in multi-component modalities, such as Fast-Neutron and BNCT, it is necessary to combine each conversion factor component to form an effective dose which is used in radiotherapy planning and evaluation. The Dose Factor Entry and Display System is designed to facilitate planner entry of appropriate conversion factors in a straightforward manner for each component. The effective isodose is then immediately computed and displayed over the appropriate background (e.g. digitized image).

We claim: 
     
       1. A method for radiotherapy planning for Boron Neutron Capture Therapy (BNCT), comprising the steps of: (a) calculating a physical distribution for an anatomical feature of a patient;   (b) entering at least one selectable conversion factor from a radiation transport module using a conversion factors entry and display tool, the radiation transport module having an output electrically coupled to a computer for loading the at least one selectable conversion factor into the computer;   (c) combining the physical distribution and the at least one selectable conversion factor to generate a biological distribution within the anatomical feature; and   (d) displaying the biological distribution as isodose contour lines superimposed over an image of the anatomical feature.   
     
     
       2. The method for radiotherapy planning as defined in claim 1 wherein the step of entering the at least one selectable conversion factor comprises the more specific step of entering the at least one selectable conversion factor at a computer keyboard. 
     
     
       3. The method for radiotherapy planning as defined in claim 2 wherein the step of entering selectable conversion factors includes the step of entering selectable conversion factors for at least one dose component selected from the group consisting of dose components comprising boron, gamma, nitrogen and fast. 
     
     
       4. The method for radiotherapy planning as defined in claim 3 wherein the step of entering selectable conversion factors includes the step of entering at least one reference value which represents the maximum dose of the anatomical feature at risk. 
     
     
       5. The method for radiotherapy planning as defined in claim 3 wherein the step of entering selectable conversion factors includes the step of entering at least one relative biologic effect factor. 
     
     
       6. The method for radiotherapy planning as defined in claim 3 wherein the step of entering selectable conversion factors includes the step of entering at least one concentration factor. 
     
     
       7. The method for radiotherapy planning as defined in claim 6 wherein the step of entering at least one concentration factor includes the specific step of specifying boron in parts per million by weight which is supposed to be present in the anatomical feature receiving the radiotherapy. 
     
     
       8. The method for radiotherapy planning as defined in claim 6 wherein the step of entering at least one concentration factor includes the specific step of specifying gamma as unity. 
     
     
       9. The method for radiotherapy planning as defined in claim 6 wherein the step of entering at least one concentration factor includes the specific step of specifying nitrogen as percent by weight in the anatomical feature as a result of radiotherapy. 
     
     
       10. The method for radiotherapy planning as defined in claim 6 wherein the step of entering at least one concentration factor includes the specific step of specifying fast as a percent by weight of hydrogen in the tissue of interest. 
     
     
       11. The method for radiotherapy planning as defined in claim 1 wherein the step of entering at least one selectable conversion factor comprises the more specific step of generating a final reference value which is the sum of the reference values. 
     
     
       12. The method for radiotherapy planning as defined in claim 1 wherein the step of calculating a physical distribution comprises the more specific step of saving the physical distribution for the anatomical feature. 
     
     
       13. The method for radiotherapy planning as defined in claim 12 wherein the method comprises the more specific steps of: (a) determining whether the biological distribution is acceptable; and   (b) if not acceptable, recalling the saved physical distribution and repeating steps (b), (c) and (d) of claim 1 until the biological distribution is acceptable, or if acceptable, terminating the method.   
     
     
       14. The method for radiotherapy planning as defined in claim 1 wherein the method comprises the more specific step of planning Fast Neutron Capture Therapy. 
     
     
       15. The method for radiotherapy planning as defined in claim 14 wherein the method comprises the more specific step of planning a hybrid combination of BNCT and Fast Neutron Capture Therapy. 
     
     
       16. A system for radiotherapy planning for treatment of an anatomical feature, said system comprising: a first graphical display for showing a conversion factors entry and display tool for entering at least one conversion factor;   a radiation transport module having an output electrically coupled to a computer for loading the at least one conversion factor into the computer;   a means for calculating a physical distribution for the anatomical feature of the patient, and for calculating a biological distribution from the calculated physical distribution and all of the conversion factors; and   a second graphical display for showing the biological distribution as isodose contour lines superimposed over the anatomical feature.